Two from Evagrius

32. Many times while I was at prayer, I would keep asking for what seemed good to me. I kept insisting on my own request, unreasonably putting pressure on the will of God. I  simply would not leave it up to his Providence to arrange what he knew would turn out for my profit. Finally, when I obtained my request I became greatly chagrined at having been so stubborn about getting my own way, for in the end the matter did not turn out to be what I had fancied it would.

and

60. If you are a theologian you truly pray. If you truly pray you are a theologian.

— from Chapters on Prayer, trans. John Eudes Bamberger 

Bamberger notes that number 60: "...is one of the key passages for the full understanding of the Evagrian identification of contemplation with prayer."